The invention relates to a screen printing screen which has a screen printing stencil carrier and a screen printing stencil.
During screen printing, a screen printing screen is arranged on a printing material or substrate. The screen printing screen has a screen printing stencil and a screen printing stencil carrier, the screen printing stencil being connected to the screen printing stencil carrier which is configured as a screen. The screen is formed by polyester or stainless steel threads which are woven with one another. In order for it to be possible to handle the screen printing screen, it is tensioned tautly in a screen printing frame.
The screen printing screen has free regions which can receive a printing medium such as an ink or a paste. If a doctor is guided over the screen printing screen, the printing medium passes through the free regions of the screen printing screen onto the substrate which is arranged under it. In order to produce fine printed tracks, screen printing stencils can be used which are produced photomechanically.
A screen having a small mesh width and thin mesh wires is required for a high resolution of the printed image and a high print quality. The smaller the wire spacings and the thinner the wires, the more complicated and the more expensive is the production of a screen of this type, however. In the case of thin mesh wires having a diameter of, for example, 5 micrometers, a high tensile stress can no longer be applied, with the result that a screen which is produced from said wires is relatively sensitive mechanically.
If a doctor were guided over a screen of this type, firstly the wires can be damaged quickly, and secondly the screen could have an abrasive effect on the doctor edge which comes into contact with the screen. The consequence would be a very low service life of the screen. In order to prevent this, a coating which is joined to the screen wires with a strong bond and increases the stability can be applied on the upper side and underside of the screen. A construction of this type has the disadvantage that it is complicated. Furthermore, the printed image and the resolution which can be achieved are influenced negatively by the additional coatings which possibly have to be applied multiple times in method steps which follow one another. If the surface to be printed has a relatively great roughness, the fine-meshed screen can be damaged rapidly, with the result that only a short service life is achieved.
It is therefore an object of the invention to provide a screen printing screen for technical screen printing, by way of which screen printing screen a high resolution can be achieved which has a high service life even in the case of rough surfaces to be printed, can be produced inexpensively in the process and does not have an abrasive effect on an associated doctor. Furthermore, printed tracks having thicknesses in the range from 0.5 micrometer to 100 micrometers are to be achieved by way of the screen printing screen.